A (meth)acrylic ester compound containing adamantane in a chemical structure thereof has high transparency and high heat resistance and is known as being usable for an optical material, a reflection-preventive coat, an optical semiconductor reflecting material, an adhesive, a photoresist and the like (Patent Documents 1 through 3). Such a (meth)acrylic ester compound is in wide use especially for a photoresist among these uses (Patent Documents 4 through 8).
Recently, size reduction is advanced with the lithography process. ArF excimer laser lithography is advanced and now uses liquid immersion exposure and even double patterning exposure. In addition, lithography using extreme ultraviolet (EUV) light, which is a target of attention as a next-generation lithography technology, and electron beam direct drawing, have been developed in various manners.
Although various developments have been made for the purpose of further size reduction, the influence of contrast deterioration caused by diffusion of acid that is generated from a photoacid generator after the exposure has become more serious as the width of the circuit is decreased. Methods for controlling the acid diffusion now proposed include a method of enlarging the structure of the photoacid generator (Non-patent Document 1) and a method of using a resin containing a monomer that contains a photoacid generator (Patent Document 9, Non-patent Document 2). Another method now proposed is a method of extending a pendant part of a resist polymer to block an acid diffusion path (Patent Documents 10 and 11). Patent Documents 12 through 14 propose a photoresist composition that has a superb sensitivity and is capable of reducing the MEEF.
Patent Documents 12 through 14 provide names of chemical substances and chemical structures, but do not describe a production method or the performance as a photoresist regarding a part of the compounds.
A reaction of generating an ester bond from carboxylic acid and alcohol uses a dehydration condensation agent such as a carbodiimide compound or the like. This reaction is known as also esterifying a tertiary hydroxyl group (Patent Document 15, Non-patent Document 3).